Support linearized loading

fpdfsdk/src/fpdf_dataavail.cpp

Index: fpdfsdk/src/fpdf_dataavail.cpp
diff --git a/fpdfsdk/src/fpdf_dataavail.cpp b/fpdfsdk/src/fpdf_dataavail.cpp
index 9ce298d0c545256d7c5abda89d8d31c660a9b05d..b0bb325896cf316f9f8433087ab0996bbcd6aed0 100644
--- a/fpdfsdk/src/fpdf_dataavail.cpp
+++ b/fpdfsdk/src/fpdf_dataavail.cpp
@@ -86,10 +86,10 @@ DLLEXPORT void STDCALL FPDFAvail_Destroy(FPDF_AVAIL avail) {
   delete (CFPDF_DataAvail*)avail;
 }
 
-DLLEXPORT int STDCALL FPDFAvail_IsDocAvail(FPDF_AVAIL avail,
-                                           FX_DOWNLOADHINTS* hints) {
-  if (avail == NULL || hints == NULL)
-    return 0;
+DLLEXPORT FX_BOOL STDCALL
+FPDFAvail_IsDocAvail(FPDF_AVAIL avail, FX_DOWNLOADHINTS* hints) {
+  if (!avail || !hints)
+    return true;

[Tom Sepez, 2015/10/14 16:57:45]

why are we inverting this return value?

[jun_fang, 2015/10/15 10:22:28]

It means data are not available when false is returned. 
Applications will keep trying when data are not available.
If avail or hints is nullptr, we think that the doc is not
a linearized doc rather than data not available.

   CFPDF_DownloadHintsWrap hints_wrap(hints);
   return ((CFPDF_DataAvail*)avail)->m_pDataAvail->IsDocAvail(&hints_wrap);
 }
@@ -120,11 +120,11 @@ DLLEXPORT int STDCALL FPDFAvail_GetFirstPageNum(FPDF_DOCUMENT doc) {
   return ((CPDF_Parser*)pDoc->GetParser())->GetFirstPageNo();
 }
 
-DLLEXPORT int STDCALL FPDFAvail_IsPageAvail(FPDF_AVAIL avail,
-                                            int page_index,
-                                            FX_DOWNLOADHINTS* hints) {
-  if (avail == NULL || hints == NULL)
-    return 0;
+DLLEXPORT FX_BOOL STDCALL FPDFAvail_IsPageAvail(FPDF_AVAIL avail,
+                                                int page_index,
+                                                FX_DOWNLOADHINTS* hints) {
+  if (!avail || !hints)
+    return true;

[Tom Sepez, 2015/10/14 16:57:45]

same here

[jun_fang, 2015/10/15 10:22:28]

The answer as above.

   CFPDF_DownloadHintsWrap hints_wrap(hints);
   return ((CFPDF_DataAvail*)avail)
       ->m_pDataAvail->IsPageAvail(page_index, &hints_wrap);
@@ -132,14 +132,14 @@ DLLEXPORT int STDCALL FPDFAvail_IsPageAvail(FPDF_AVAIL avail,
 
 DLLEXPORT int STDCALL FPDFAvail_IsFormAvail(FPDF_AVAIL avail,
                                             FX_DOWNLOADHINTS* hints) {
-  if (avail == NULL || hints == NULL)
-    return -1;
+  if (!avail || !hints)
+    return PDF_FORM_AVAIL;
   CFPDF_DownloadHintsWrap hints_wrap(hints);
   return ((CFPDF_DataAvail*)avail)->m_pDataAvail->IsFormAvail(&hints_wrap);
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFAvail_IsLinearized(FPDF_AVAIL avail) {
-  if (avail == NULL)
-    return -1;
+DLLEXPORT int STDCALL FPDFAvail_IsLinearized(FPDF_AVAIL avail) {
+  if (!avail)
+    return PDF_LINEARIZATION_UNKNOWN;
   return ((CFPDF_DataAvail*)avail)->m_pDataAvail->IsLinearizedPDF();
 }